Turbochargers are forced-induction devices used with internal combustion engines and are utilized to increase the pressure and density of intake air provided to the engine. Exhaust gas from the engine is routed to the turbocharger and is utilized to drive a turbine wheel. The torque generated by the turbine wheel rotates a compressor wheel via a turbo shaft, and the compressor wheel pressurizes intake air for supply to the engine. By pressurizing the intake air, the amount of air and fuel that can be forced into each engine cylinder during an intake stroke of the engine is increased. This produces an increased power output relative to a naturally-aspirated engine.
Turbochargers may be employed in demanding environments of vehicle engine compartments, or other applications (e.g., for electricity generation). The internal moving components of turbochargers further operate at very high revolutions and at high temperatures. Due to these operating conditions, it is important to continually lubricate the moving turbocharger components to cool the components and reduce wear. To supply lubricant to the internal components, turbochargers are connected to the engine lubrication system and are supplied pressurized oil. The pressurized oil is routed to bearing cartridges rotatably supporting the turbo shaft connecting the turbine wheel and compressor wheel and is then returned to the engine lubrication system for filtering and cooling of the oil.
To contain lubricant (e.g., engine oil) in the turbocharger lubrication system, seals and other features are employed at various points along the lubrication path to direct lubricant away from undesired areas and turbocharger components (e.g., away from the compressor housing). Due to the high rotation speeds, high temperatures, need for lubricant containment, and manufacturing and assembly cost and complexity, it may be advantageous to reduce the number of turbocharger components, including those along the lubrication path to reduce the need for additional seals and sealing techniques.
It would be advantageous to provide a turbocharger that improves on, or resolves, disadvantages with conventional turbocharger designs, reduces the complexity in design and assembly, and increases performance and durability of the turbocharger lubrication system and the turbocharger overall.